I have a 7042234 Carb from a 72 Cadillac. The base plate, front center below the power piston has a slot. in this slot is a metal "blade" for lack of a better term. It appears to have been installed thru a plugged hole from the front of the plate. What is this? Should it move-it does not? Is it anything to be concerned with? I find no reference to it in the book, instruction sheet with the rebuild kit or any other source. Thanks in advance.